This invention relates in general to valves for use in vehicle brake systems that utilize pressurized air, and in particular to a control valve for controlling the flow of pressurized air to the brakes of a vehicle.
Large commercial combination vehicles having a tractor portion and a trailer portion often include a vehicle braking system that utilizes compressed air. Air brake systems usually include a combination of three different braking systems: the service brakes, the parking brakes, and the emergency brakes. The service brake system applies and releases the brakes when the driver uses the brake pedal during normal driving situations. The parking brake system applies and releases the parking brakes when the parking brake control is engaged. The emergency brake system utilizes portions of the service brake and parking brake systems to stop the vehicle in the event of a brake system failure. Some air brake systems include a control brake valve that allows the operator to manually control the services brakes on the trailer portion of the vehicle independently of the tractor brakes. Such control valves are particularly useful in situations where a manually-controlled pressure graduation function is desired.
Installing trailer control valves on different vehicles often involves variable plumbing configurations, and properly orientating the pneumatic lines attached to the control valve may involve the use of valve bodies having either vertically oriented ports or horizontally oriented ports. Additionally, the handle that is typically attached to the body of the control valve may be configured for either linear translation or for rotational translation depending on the arrangement of the dashboard or steering column to which the valve is attached. Thus, one of at least four different valve handle/body assemblies will often be used based on the vehicle and system in question. Manufacturing four or more versions of the same valve is redundant and expensive; thus, there is a need for a control valve that provides multiple handle and port configurations and that is compatible with a variety of vehicles and brake systems.